It is a well-known fact that the main work of cleaning a swimming pool--whether indoor or outdoor--is the removal by suction, or vacuuming, of the sediment which accumulates. Various types of cleaning apparatus have been developed for that purpose, manually operated or fully automatic, and powered by electricity, water pressure, or hydrosuction.
The best cleaning effect is achieved with hydrosuction since all the sedimentary material, some of it slimy, is conveyed through the suction hose directly to the filter installation of the circulating pump, from whence it is carried directly into the sewer system by means of the backwash operation. A machine operating in this manner is disclosed, for example, in U.S. Pat. No. 3,979,788 and, in a modified form, in Swiss Patent No. 648,893. These designs operate perfectly well in swimming pools of any outer shape, provided that the bottom is flat and is not too sharply inclined. For swimming pools of American design, however, which often have gradual transition between the bottom and the walls, as well as diving depressions, the aforementioned apparatus cannot be used. A machine designed for this kind of pool, described in U.S. Pat. No. 4,156,948, can adhere to walls of any steepness by means of a suction disk and is propelled by tapping against the suction disk. This apparatus has only limited possibilities of propulsion and directional control and is continually getting stuck.
It is an object of this invention to provide an improved pool cleaning machine which, regardless of the shape or form of the pool, with floors of any steepness merging into vertical walls, is capable of adhering, moving along, and changing direction without getting stuck at obstacles or climbing above the surface of the water.
To this end, in the machine for cleaning swimming pools according to the present invention of the type initially mentioned, the two suction disks are rotatingly mounted in the housing, and means are provided for driving the suction disks in the direction of rotation.